March wheat pest and disease control methods
March is the first critical period for spring control of wheat pests and diseases in our province. The main pests and diseases occurring include wheat sharp eyespot, wheat spider mites, and seedling-stage aphids. In particular, if wheat sharp eyespot in areas with above-moderate occurrence is not effectively controlled, it will cause serious impact on wheat production.
When wheat sharp eyespot occurs at the seedling stage, the lesions extend to the stem, and the first and second internodes at the base of the stem turn black and rot, causing the plant to die. In the late growth stage of wheat, plants with severe stem disease often fail to produce ears, forming "blasted heads," or although ears can emerge, the grains are few and shriveled, forming "white heads." White heads in the field are mostly from individual infected plants, which are easily broken off from the lesion at the base of the diseased stem. Wheat sharp eyespot in our province mainly occurs year-round in high-yield cultivation wheat areas with sufficient fertilizer and water, as well as in the northern part of Huaibei and the heavy occurrence areas along the Huai River. In these wheat areas, the diseased plant rate of wheat sharp eyespot can reach as high as 20-40% year-round. Under natural conditions, diseased wheat generally suffers a yield reduction of about 5-10%, and in years with severe disease, the diseased plant rate and yield loss will be even higher. Wheat sharp eyespot has become an important disease affecting the stability of wheat yield across the province. In addition, in wheat fields currently with poor growth and those severely affected by drought earlier, wheat spider mites and seedling-stage aphids will also become factors affecting wheat yield. In order to timely and effectively control wheat sharp eyespot while also controlling wheat spider mites and wheat seedling aphids, the following technical control recommendations are proposed:
Control targets: Focus on sharp eyespot, while also controlling wheat spider mites and seedling-stage aphids in some wheat areas.
Control thresholds: sharp eyespot diseased plant rate 20%; wheat spider mites 200 per chi of row length; seedling aphids 500 per hundred plants.
Control pesticides: For controlling sharp eyespot, use 150 mL of 12.5% Jinglaya aqueous solution (Wenmeiqing) per mu, or 50 g of 12.5% diniconazole (Heguoli) wettable powder, or 50 g of 20% validamycin wettable powder; for controlling wheat spider mites, use 30 mL of 10.2% abamectin-pyridaben emulsifiable concentrate per mu, or 30 mL of 15% pyridaben (Basiben) emulsifiable concentrate; for controlling seedling aphids, use 20 g of 24% anti-aphid imidacloprid or 20 g of 10% imidacloprid wettable powder per mu.
Apply sufficient and uniform spray: For motorized sprayers, dilute with 15 kg of water per mu; for manual sprayers, dilute with 30-40 kg of water. Choose to apply pesticide in the morning when there is dew, and appropriately increase the amount of water used so that the pesticide solution can flow to the base of the wheat plants. In severe sharp eyespot areas, spray once more 10 days after the first spray.